This graph is meant to "make the data tell their story". It is hard to read, though. Let us ask what the right statistical approach would be.
The practical question we want to answer is: by how much does GDP growth prior to elections drive the likelihood of the incumbent to be re-elected?
That translates into the following statistical question: how does the (binary win/lose) outcome of the election depend on the (continuous) growth rate?
The tool to use here is binary logistic regression. When doing that you find that none of the quarters predicts the outcome. Also the trend across the quarters does not predict the outcome (all at 95% significance). What does predict the outcome, though, is average growth rate over the past 6 quarters (with a P-value of 0.9%, that is: there is a 99.1% chance the correlation we see is real).
In other words: people seem unlikely to vote out presidents who maintained a high average growth but will do it when they believe the average growth is low. Trends or particular quarters matter much less, if at all.
Binary logistic regression leads to a prediction equation, which can be used, together with those quarters we have available for Obama, to make a prediction for this coming election. The result is: chances are very slim indeed for the incumbent - according to the data.
To my knowledge, different from "classical regression", binary logistic regression does not provide an R^2 value that would allow to see how much room there is for other influence factors to drive the outcome.
I will publish soon the graphs on my blog. http://blog.ohlermichael.de/

Michael Ohler, Principal with Breakthrough Management Group International

Voters are usually good at sniffing out the correct trend of history. They elected Lincoln, FDR, Reagan, and many other great and near-great presidents at exactly the right time.

If this tendency holds true they will re-elect President Obama. The Era of the One Percent came to an ignominius end in 2008. Romney, though a good man, is a tool of the 1%. Obama, though not the sharpest tool in the shed on economic policy, is the friend of the 99%. The people instinctive understand this and will re-elect him, IMHO.

Barak has set all kinds of records for the US economy. $10 Trillion in nw debt, debt now is larger than GDP, the highest unemployment numbers since Roosevelt, foodstamps more than doubled, SS now borrowing from China t pay current beneficiaries. A nonexistent foreign policy.
In short this is what everyone knew would happen when someone with 0 eperience and went thu life as a quota receiptent was elected. he is simply over his head

Telling that you only went back to '48. Is Roosevelt ancient history? And Clinton: At the end of his second term, a very good economic time, his chosen successor failed, though narrowly. So, why does TE think only in terms of economics? Oh, yeah..your name.

I understand where u are coming from. The Muslims are mostly emotional and the logic takes a back seat.Obama in question is inbetween the hard rock and elections and his hands are tied with focus on winning the second term. He will end the war in Afghanistan and possibility of stopping the drones. I am not in favour of Al-quada ruling Pakistan. would you?

You might want to broaden your circle of Muslim acquaintenances. I can assure you that, as a group, they are every bit as rational (or emotional) as any other group (religious, ethnic, or racial) you would care to name.

Personally I think Barak is the worst Us president since Jimmy Carter but looking at your questions I would have to say WHY???
Drone attacks are removing the savages from the battlefield
Casualties?? The only ones that matter are the NATO ones
Geneva Convention allows the US to use what ever means necessary against armed enemy combatants

Nobody denies that there are some murderous insane fanatics who also are (or at least claim to be) Muslims. There are also some who are (or claim to be) Christians, Hindus, Jews, Buddhists, etc., etc. That's my whole point -- get a little broader sample of those belonging to any religion before you condemn it out of hand.

One only needs to pick up and read a newspaper on any given day to see who and what the problems of this century are. Its not Jews, Hindu's,Buddhists or Christians its the mooslims.
Being in denial isn't a logical response

I suppose it depends on which newspapers you pick up and read. I recall a few years back, for just one example, when most of the news of sectarian violence came from Hindus in India, mostly trashing mosques and attacking Muslims. So no, I don't think it is denial to say that it is Muslims who are the problem.

For that matter, it occurs to me that, judging by the newspapers, crime in America is expolding and everyone is at serious risk of attack at all times. Although, if you trouble to look at the data, you discover that crime rates have been dropping for a couple of decades now. So perhaps the newspapers (or the TV news, which is at least as bad) are not the best possible source for seeing what problems exist and what their characteristics are.

Strange when I google your point about sectarian violence against mooslims by Hindus or Buddhists all I found was moooslims raping a 8 year old girl or a perceived slight on facebook Sorry the posters on the subways in NY City define the issue precisely 'savages to describe moooslims

Perhaps if you looked at the past couple of decades of the Bharatiya Janata Party (Hindu National Party) you will find more.

Although, since Google pops up pages of entries for "hindu muslim violence," perhaps you just have extremely effective filters on your browser to keep unwanted data out. In which case, no doubt you won't see anything.

Growth is not going to happen any more, so we need a new way to measure where the economy is going. maybe we need to measure ecological health instead of economic health. it will give us a better picture of community health

Vote for Green Party candidate Jill Stein for President, neither Obama nor Romney have a clue about where the economy is really going.

With Barak as president even he has no idea where the economy is going, but Romney will fix that in his 1st 6 months. The Greens is just the party of NO. Every idea they have ever pushed when implemented made things worse not better

Indeed,and I have reflected these same conclusions in a few of the comments that I have made.However there are those who are either daft or dishonest and who would like to detract from the good work that President Obama is doing.I am not an American, and so have no vested interest in the outcome of the forthcoming US presidential election.However it is incredible that a person who is so obviously trying to do his level best should find himself so distracted.

There's too much data to absorb. As we move toward the election, it might become apparent which candidate is going to get elected. But nobody has gotten re-elected with unemployment this high. Obama's got his work cut out.

Please remember that America's history did not begin after the Second World War, and that there were 33 presidents before Ike that are not included in this study (of course, due to data limitations). I'm certain that there were presidents elected under harsher economic conditions than the ones we face now. The American electorate is ever-dynamic, economic and social conditions are always changing. I feel like much of these predictions are treating conditions like they are somehow static between 1952 and today. Each candidate had a unique set of issues to deal with, and a different electorate to pander to.

Just because we have data doesn't mean that we have the story. Voters deciding between Barack Obama and Mitt Romney are decidedly different from those deciding between Dwight Eisenhower and Adlai Stevenson. I view these predictors with (at least) a grain of salt.

Much like the market for magic diet pills, the desire to find a single metric to predict the future is resistant to critical thought.
There are numerous websites and programs to evaluate graphics for use by color impaired. It is a trivial bit effort to find and use them. I found them useful when I needed to make maps for a color impaired co-worker.

The US economy is in the worst FINANCIAL shape it has ever been since the Great Depression.Fortunately living standards are so much higher today and a financially-caused production and employment contraction translates into a nuisance, not a catastrophe.

Thankfully, too, the Fed-Treasury duo have managed to prevent the 1929-1934 free fall that contracted GDP by 50%.(Under Obama and the last days of Bush II).

Except for those two important caveats we all know the situation is serious enough to make post-WWII comparisons somewhat out of place.

2012 should be compared to 1936, and on that basis Obama has fared better than FDR, even though his actions have been managerial, not transformational, unlike those of FDR, who really changed the rules of the game.

It could be argued that it was the power and mandate accumulated by the Fed and Treasury under FDR that has given Obama the tools to sail through this storm with far more ease than a pre-FDR president ever would have.

BTW, either I am color-blind or the colors in the chart for non-average candidates are indistinguishable.

Up to 10% of men are color blind.
And they tend to vociferously quarrel with the Chart Makers on The Economist.
They generally are blind to their condition.
I think you need to look at some Ishihara Plates to firm up your diagnosis.
And maybe look at your driving record for Moving Violations.

The software that I use to create graphs automatically provides icons to differentiate the various data series. And includes them on the key as well. Pity the Economist doesn't choose to use something like that. (Perhaps they expect that, at the scale used in figures printed in the magazine, such icons would be more hinderance than help.)

What some people don't understand is that regardless of who wins the presidential elections, he won't be able to fix the economy overnight. It takes years to fix a broken economy, and electing Romney will not change anything.